Services and Water Infrastructure were incremental revenue contributions from the Complete, Agua Libre and Basic, HB Rentals, Nuverra, Breakwater and Cypress acquisitions. For the year ended December 31, 2022, our Water Services, Water Infrastructure and Oilfield Chemicals revenues constituted 57.6%, 19.5% and 22.9% of our total revenue, respectively, compared to 51.6%, 20.2% and 28.2%, respectively, for the year ended December 31, 2021. The revenue changes by reportable segment are as follows:
Water Services. Revenue increased $405.3 million, or 102.8%, to $799.4 million for the year ended December 31, 2022, compared to $394.1 million for the year ended December 31, 2021. The increase was primarily attributable to higher demand for our services coupled with increased pricing in comparison to the year ended December 31, 2021. The increase was also impacted by incremental revenue contributed by the Complete, Basic, HB Rentals, Nuverra and Breakwater acquisitions.
Water Infrastructure. Revenue increased by $115.6 million, or 74.7%, to $270.4 million for the year ended December 31, 2022, compared to $154.8 million for the year ended December 31, 2021. The increase was primarily attributable to higher demand for our services in comparison to the year ended December 31, 2021. The increase was also modestly impacted by incremental revenue contributed by the Complete, Agua Libre, Nuverra, Breakwater and Cypress acquisitions.
Oilfield Chemicals. Revenue increased $101.9 million, or 47.2%, to $317.6 million for the year ended December 31, 2022, compared to $215.8 million for the year ended December 31, 2021. The increase was primarily attributable to higher demand for our services, particularly our proprietary friction reducer product offerings, in comparison to the year ended December 31, 2021.
Costs of Revenue
Costs of revenue increased $482.9 million, or 64.9%, to $1.2 billion for the year ended December 31, 2022, compared to $743.8 million for the year ended December 31, 2021. The increase was comprised of a $297.4 million increase in Water Services costs, a $87.5 million increase in Water Infrastructure costs and a $74.5 million increase in Oilfield Chemicals costs. Depreciation and amortization expense also increased by $23.5 million. For the year ended December 31, 2022, inflation also impacted variable costs for labor, fuel and services. We were able to pass some of these increased costs to customers with surcharges and pricing increases.
Water Services. Costs of revenue increased $297.4 million, or 85.8%, to $644.1 million for the year ended December 31, 2022, compared to $346.7 million for the year ended December 31, 2021. Cost of revenue as a percent of revenue decreased to 80.6% from 88.0%, due primarily to economies of scale from higher revenue activity
Water Infrastructure. Costs of revenue increased $87.5 million, or 75.5%, to $203.4 million for the year ended December 31, 2022, compared to $115.9 million for the year ended December 31, 2021. Cost of revenue as a percent of revenue slightly increased to 75.2% from 74.9%, due to increased pricing for many water sources partially offset by a higher relative contribution of high margin disposal revenue.
Oilfield Chemicals. Costs of revenue increased $74.5 million, or 39.0%, to $265.6 million for the year ended December 31, 2022, compared to $191.1 million for the year ended December 31, 2021. Cost of revenue as a percent of revenue decreased to 83.6% from 88.6%, due primarily to higher utilization and cost absorption at our manufacturing facilities.
Depreciation and Amortization. Depreciation and amortization expense increased $23.5 million, or 26.1%, to $113.5 million for the year ended December 31, 2022, compared to $90.0 million for the year ended December 31, 2021, due primarily to a higher fixed asset base related to acquisitions occurring after June 30, 2021.